For a short period of time, the frictional driving force acting on the wheels of the 2.3-Mg van is FD = (600t2) N, where t is in seconds. (Figure 1) Figure FD <1 of 1 Part A If the van has a speed of 22 km/h when t = 0, determine its speed when t = 5 s. Express your answer to three significant figures and include the appropriate units. μA S → Ⓒ v=3.32 * Incorrect; Try Again; m Provide Feedback S Submit Previous Answers Request Answer ? attempts remaining

We often think of friction and air resistance as forces that we want to minimize because they can hinder the motion of an object.  But they are not always undesirable, and in fact, can be an essential element in a machine or process. Identify one or two applications that depend on friction and air resistance.  Explain how friction or air resistance works in those situations and what would happen if there were no friction or air resistance.  Your initial post should be 75-150 words in length and is due on Sunday.

you are driving down the road and are speeding. You apply the brakes on your car until you slow down to 22.4 m/s. A computer plots the force versus time for the vehichle and then measures the area under the curve. The area is -18950 N per s. The total breaking is 5.4 seconds. The combined mass of the car is 1200 kg. How fast were you moving before applying the breaks? What is the average force applied by the road to thr car before breaking?

Answer to 5)1.96

Blocks 1 and 2 are moving to the right on a frictionless surface by the tension TB = 36 N as shown. m1 = 2.0 kg, and m2 = 3.2 kg. What is the magnitude of the acceleration of block 2, in m/s²? Your answer needs to have 2 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement. m₁ TA m₂ TB

Figure shows a block of mass m resting on a 20° slope. The block has coefficients of friction μ = 0.78 and = 0.47 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. (Figure 1) Figure Part A m= Part B What is the minimum mass m that will stick and not slip? Express your answer to three significant figures and include the appropriate units μA Value a= m 20⁰ Value Units www Units ? If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will Express your answer to three significant figures and include the appropriate units. 2 kg 1 of 1 ?

Some physics students are studying periodic motion using an oscillating mass on a spring. After collecting data, they sketched the position versus time graph shown. If the spring constant is 5.84N/m, then what is the mass, in kilograms?

A car with a mass of 1.2x103 kg is skidding to a stop along a horizontal surface. The car decelerates from 32.2 m/s to rest in 3.89 seconds. Assuming negligible air resistance, determine the coefficient of friction between the car tires and the road surface. Answer: μ =_________ (no units) (rounded to nearest hundredths place)

Question 3. The cart shown in figure below moves with constant deceleration changing the speed from v0 = 5 m/s to v1 = 1 m/s. After 2 seconds when it reaches the speed v1 it suddenly stops. Write the displacement of the mass as a function of time. Mass m moves without friction on the surface of the cart. Assume positive direction from left to right (direction of motion of the cart). Numerical values: m = 2 kg, k = 1.152 kN/m. V k Ans: x(t) = 3.472 cos 24 t + 41.6 sin 24 t (mm) m L

A sled of mass 87 kg is being pushed up a slope with an applied force of 853 N. The slope is inclined with an angle of 34 degrees with respect to the horizontal. The coefficient of friction between the sled and the hill is 0.29. The acceleration of the crate (in m/s²) is: