An elevator of mass 800 kg acclerates at 3.0 m/s^2 Down. What is the force exerted on the elevator by the cable?
A 0.14 kg baseball requires a velocity of about 75 m/s in order to clear the fence in right field. What is te average net force applied to the ball by the bat if the ball was at rest when struck (on a tee) and is in contact with the bat for 6.0 x 10^-4 seconds?
A tennis racket, in contact with a ball (55 g) for 0.00050 s changes the ball's velocity from 30m/s [East] to 40 m/s [West]. What is the average force exerted on the ball by the racket?
A 0.25 kg model rocket acclerates from 15 m/s to 40 m/s in 0.60 s. Calculate the force(s) the escaping gases exert on the rocket?
A submarine rescue chamber has a mass of 8.2 tons (8200 kg) and safely descends at a constant velocity of 0.4 m/s, determine the force exerted by the bable and the water (buoyant force) on the chamber.
A 41 kg weather balloon 24 km above earth is travelling at a constant velocity of 5.0 m/s [W]. If g at this altitude is 9.7 m/s^2 [Down], draw a free body diagram for the baloon.
Two boxes, one with a mass of 60 kg and the other with a mass of 90 kg are in contact and on a smooth surface. A 800 N force is exerted on the 60 kg box toward the 90 kg box. Calculate:
a) The accleration of the boxes.
b) The magnitude of the action / reaction forces between the boxes.
Nasta has a rocket that has a mass of about 3.8 x 10^6 kg and its first stage engines exert a thrust of about 5.0 x 10^7 N.
a) What is the force of gravity on the rocker at the surface of the earth?
b) Calculate the net force on the rocket at lift-off.
c) Calculate the inital accleration of the rocket.
d) Assuming that the engine thrust is constant, what will happen to the accleration of the rocker as the fuel burns?
e) Why is the first stage of the rocket jettsoned after the fuel is consumed?
Peri Chute, a famous skydiver, has a mass of 65 kg (including the parachute). Peri opens her parachute when she reaches a velocity of 4.0 m/s [Down]. The parachute opens and exerts an upward force of 337 N. Calculate:
a) Peri's accleration just after her parachute has opened.
b) Her velocity 2.0 s after opening her parachute.
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