Related questions
Question
thumb_up100%
A skateboarder with mass ms = 46 kg is standing at the top of a ramp which is hy = 3.3 m above the ground. The skateboarder then jumps on his skateboard and descends down the ramp. His speed at the bottom of the ramp is vf = 6.6 m/s.
a)Write an expression for the work, Wf, done by the friction force between the ramp and the skateboarder in terms of the variables given in the problem statement.
b)The ramp makes an angle θ with the ground, where θ = 30°. Write an expression for the magnitude of the friction force, fr, between the ramp and the skateboarder.
c)When the skateboarder reaches the bottom of the ramp, he continues moving with the speed vf onto a flat surface covered with grass. The friction between the grass and the skateboarder brings him to a complete stop after 5.00 m. Calculate the magnitude of the friction force, Fgrass in newtons, between the skateboarder and the grass.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 4 steps with 1 images
Knowledge Booster
Similar questions
- A block of mass ?=0.350kg is released from rest, from a curved ramp of height h= 42.0 cm (point A in the figure). The block slides down frictionless to the bottom of the ramp to point B. a) What is work done by gravity when the block moves from A to B? b) What is the speed of the block at the bottom of the ramps (point B in the figure)? c) The box continuesto slide frictionless and compress a spring a distance Δ?=8.20cm until it stops at point C. What is the spring constant k of the spring? d)What is the elastic potential energy stored in the spring when the block is at point C?arrow_forwardA child of mass m = 16 kg slides down a slide of height h = 2.7 m without friction. Let gravitational potential energy be zero at ground level. a)Write an expression for the child's total mechanical energy, E, at the top of the slide, in terms of the variables in the problem and the acceleration due to gravity g. b)Calculate the change in the child's potential energy, ΔU in joules, from the top to the bottom of the slide at ground level (i.e. ΔU = Uground - Utop). c)What is the child's final speed, vf in m/s?arrow_forwardThe overworked Amazon delivery person is driving up a steep hill with an incline of 26° when a box they forgot to secure starts sliding toward the back of the truck. The 3.5 kg box starts from rest near the drivers seat and slides 2.1 m along the floor to the rear door. The coefficient of kinetic friction between the box and the floor is 0.36. What is the work done by the weight of the box? Wmg 31.6 J What is the work done by the Normal Force? WN = 0 What is the work done by the frictional force? Wfk = 23.31 What is the net work done on the box? Wnet What is the change in kinetic energy for the box? AKE How fast is the box moving just before it hits the rear door? Vfinal = J J X J J msarrow_forward
- A) A 1390 kg car accelerates uniformly from rest to 10.4 m/s in 2.87 s. Find the work done on the car in this time interval. Answer in units of kJ. B) Find the average power delivered by the en- gine in this time interval. Answer in units of hp. C) Find the instantaneous power delivered by the engine at t = 1.5 s. Answer in units of hp.arrow_forwardA block of mass m = 2.00 kg is pushed a distance d = 7.80 m along a frictionless, horizontal table by a constant applied force of magnitude F = 17.0 N directed at an angle θ = 26.0° below the horizontal as shown in the figure below. a) Determine the work done on the block by the applied force. b) Determine the work done on the block by the normal force exerted by the table. c) Determine the work done on the block by the gravitational force. d) Determine the work done on the block by the net force on the block.arrow_forwardA 32-kg block is pulled along the ground for a distance of 4.9 m by a 57 N force at an angle of 21 degrees with respect to the horizontal. The coefficient of kinetic friction is 0.21. a) Find the work done (in J) by the applied force. b) Find the work done (in J) by the normal force exerted by the ground. c) Find the work done (in J) by the force of gravity.arrow_forward
- A 10.0-kg particle, starting at point A at a height of 5.00 m above the ground with an initial velocity of 8.00 m/s, is moving down the curved runway. Upon leaving the runway, the particle shoots straight upwards to a height of 7.00 m above the ground before falling back down. What is the work done by nonconservative forces on the ball?arrow_forwardYou pick up a barbell with weights (total mass: 100.0 kg) from the ground to approximately 0.800 m above the ground (roughly equivalent to doing a deadlift). Once it has been lifted, you then carry it 10.0 m at a steady speed before stopping and finally gently lowering the barbell back to the ground. How much work have you done on this barbell in J?arrow_forwardStarting from rest, a 6.2-kg block slides 3.2 m down a rough 37-degree incline. The coefficient of kinetic friction between the block and the incline is μk = 0.55. a) Determine the work done by the friction force between block and incline. b) Determine the work done by the normal force. c) Determine the net work done on the block.arrow_forward
- D & E PLEASEarrow_forwardA force with a magnitude of 60 N is applied at an angle theta= 50 to the horizontal to an object initially at rest, displacing it 5 m from its initial location. The object weighs 50 kilograms and there is no friction. After this displacement, the force is no longer applied. Determine the work being done by the force? How fast is the object when the force is removed? When the force is no longer exerted, the item falls down a 10-meter-high cliff. When it reaches the ground, what is its velocity? When it strikes the ground, it slides along the ground, which has a coefficient of kinetic friction of 0.25. How far does it go before coming to a stop?arrow_forward
arrow_back_ios
arrow_forward_ios