A 44.0-kg projectile is fired at an angle of 30.0° above the horizontal with an initial speed of 140 m/s from the top of a cliff 146 m above level ground, where the ground is taken to be y = 0. (a) What is the initial total mechanical energy of the projectile? (Give your answer to at least three significant figures.) (b) Suppose the projectile is traveling 99.2 m/s at its maximum height of y = 350 m. How much work has been done on the projectile by air friction? (c) What is the speed of the projectile immediately before it hits the ground if air friction does one and a half times as much work on the projectile when it is going down as it did when it was going up? m/s

The figure here shows a plot of potential energy U versus position x of a 0.876 kg particle that can travel only along an x axis. (Nonconservative forces are not involved.) Three values are UA = 15.0 J, Ug = 35.0 J and Uc = 45.0 J. The particle is released at x = 4.50 m with an initial speed of 7.96 m/s, headed in the negative x direction. (a) If the particle can reach x = 1.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (b) magnitude and (c) direction of the force on the particle as it begins to move to the left of x = 4.00 m? Suppose, instead, the particle is headed in the positive x direction when it is released at x = 4.50 m at speed 7.96 m/s. (d) If the particle can reach x = 7.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (e) magnitude and (f) direction of the force on the particle as it begins to move to the right of x = 5.00 m? UcT UB 4 x (m) (a) Number i Unit (b) Number i Unit (c) (d) Number i…

A block of mass m= 5.00 kg is reased from point A and slides dows the frictionless track shown in the figure. calculate the speed of the block at piont B and C. g= 9.8m/s2

A shooting star is a meteoroid that burns up when it reaches Earth’s atmosphere. Many of these meteoroids are quite small. Compare the kinetic energy of a shooting star to that of a moving car. (a) What is the kinetic energy of a meteoroid of mass 4.84 g moving at a speed of 49.2 km/s? (b) What is the kinetic energy of a 1054-kg car moving at 28.9 m/s (64.6 mi/h)?

In the figure, a 2.8 kg block is accelerated from rest by a compressed spring of spring constant 620 N/m. The block leaves the spring at the spring's relaxed length and then travels over a horizontal floor with a coefficient of kinetic friction -0.241. The frictional force stops the block in distance D-8.2 m. What are (a) the increase in the thermal energy of the block-floor system, (b) the maximum kinetic energy of the block, and (c) the original compression distance of the spring? No friction

A child starts at rest and slides down a frictionless slide as in picture. The bottom of the track is a height h above the ground. The child then leaves the track horizontally, striking the ground at a distance d as shown. (a) Using conservation of energy, find the speed of the child at the end of the slide (b) Using your answer to part (a) and equations related to a projectile, determine the initial height H of the child above the ground in terms of h and d. Н d

The figure here shows a plot of potential energy U versus position x of a 0.898 kg particle that can travel only along an x axis. (Nonconservative forces are not involved.) Three values are UA = 15.0 J, UB = 35.0 J and Uc = 45.0 J. The particle is released at x = 4.50 m with an initial speed of 7.52 m/s, headed in the negative x direction. (a) If the particle can reach x = 1.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (b) magnitude and (c) direction of the force on the particle as it begins to move to the left of x = 4.00 m? Suppose, instead, the particle is headed in the positive x direction when it is released at x = 4.50 m at speed 7.52 m/s. (d) If the particle can reach x = 7.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (e) magnitude and (f) direction of the force on the particle as it begins to move to the right of x = 5.00 m? Uc UB UA 2 4 x (m) (a) Number i Unit (b) Number i Unit (c) (d)…

A 12.0 kg box is given an initial push that starts it sliding across the floor. It eventually comes to a stop. If the box has an initial velocity of 3.5 m/s, how much work is done by friction to cause it to come to a stop? (Yes, you are correct, you do not know the coefficient of friction.)

A sled is given a push across a horizontal surface. The sled has a mass m, the push gives it an initial speed of 3.40 m/s, and the coefficient of kinetic friction between the sled and the surface is 0.150. (a) Use energy considerations to find the distance (in m) the sled moves before it stops. m (b) What If? Determine the stopping distance (in m) for the sled if its initial speed is doubled to 6.80 m/s. m

The figure here shows a plot of potential energy U versus position x of a 0.877 kg particle that can travel only along an x axis. (Nonconservative forces are not involved.) Three values are UA = 15.0 J, Ug = 35.0 J and Uc = 45.0 J. The particle is released at x = 4.50 m with an initial speed of 7.39 m/s, headed in the negative x direction. (a) If the particle can reach x = 1.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (b) magnitude and (c) direction of the force on the particle as it begins to move to the left of x = 4.00 m? Suppose, instead, the particle is headed in the positive x direction when it is released at x = 4.50 m at speed 7.39 m/s. (d) If the particle can reach x = 7.00 m, what is its speed there, and if it cannot, what is its turning point? What are the (e) magnitude and (f) direction of the force on the particle as it begins to move to the right of x = 5.00 m? Uc UB UA 4. x (m) (a) Number | Unit (b) Number Unit (c) (d) Number…