The muzzle velocity of a bullet fired from a new rifle is 100 m/s. Neglecting ai
ID: 1442156 • Letter: T
Question
The muzzle velocity of a bullet fired from a new rifle is 100 m/s. Neglecting air resistance, at the end of one second a bullet fired straight up into the air will have traveled a distance of 100 m. 4.9 m (100 + 4.9) m. (100 - 4.9) m none of these An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 second, the object will have a speed of 50 m/s. 10 m/s 5 m/s. 20 m/s. 100 m/s. Starting from rest, the distance a freely falling object will fall in 0.5 second is about 10 m. 1.00 m. 1m. none of the above If a car accelerates from rest at 2 meters per second, its speed 3 seconds later will be 2 m/s. 6 m/s. 3m/s. 4m/s In each second of fall, the distance a freely falling object will fall is about 10 m. the same, but not 5 m or 10 m. increasing. about 5 m. none of these If a rocket initially at rest accelerates at a rate of 50 m/s^2 for one minute, its speed will be 3000 m/s. 3600 m/s. 50 m/s. 500 m/s. A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting 23 point. During this time the acceleration of the ball is always directed upward. opposite its velocity. in the direction of motion. directed downward. If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be 9.8 meters per second per second. greater than 9.8 meters per second per second. Jess than 9.8 meters per second per second.Explanation / Answer
17) distance = vbullet*t = 100m/s*1s = 100m
Answer is A) 100m
18) vi= 0m/s , a= -20m/s^2
vf= vi+at = 0 -20m/s^2*5s = -100m/s
|vf|= 100m/s
19) vi=0m/s
h=vi*t-1/2gt^2 = 0*0.5 – ½*9.8*0.5^2 = 1.225 m = 1.0m
20) a=2m/s^2 , t= 3s
vf=vi+at = 0 +2*3 = 6m/s
21) g= 10m/s^2 , t= 1.0s
h=vi*t-1/2gt^2 = 0*0.5 – ½*10*1.0^2 = 5.0m
22) a= 50m/s^2 , t= 1min= 60s
vf= vi +at = 0 + 50*60 = 3000 m/s
23) For freely fall bodies acceleration is due to gravity acted downward always. Hence correct answer is D).
24) For freely fall bodies acceleration is due to gravity ( g= -9.8m/s^2) acted downward always. Hence correct answer is A).