-- Gravity adds 9.8 m/s to the downward speed of any object, every second ... as long as there are no other forces messing with it.
-- In 0.6 sec, gravity added (0.6x9.8)= 5.88 m/s to the downward speed of this ball.
-- This ball didn't start from zero. You threw it down with an initial speed of 1 m/s. So after 0.6 sec, with the help of gravity, its speed is
(1) + (5.88) = 6.88 m/s .
Pick choice-C .
Notice that we don't care how high it was off the ground when you threw it, just as long as it was high enough to keep falling for 0.6 sec without hitting the ground.
Answer:
The potential energy increases and the kinetic energy decreases
Answer:
A
Explanation:
the balancing is correct in the first one
Answer:
75 km/h
Explanation:
Speed = Distance divided by Time.
The train went a distance of 300 km in 4 hours. Therefore, the speed of the train is: 300 divided by 4 = 75 km/h
F(friction) = u F(normal)
so, F(friction) = (.30)(60*9.81) = 177 N
F = ma
so, 177 = (60)a, a = 177/60 = 2.9m/s^2
v(final)^2 = v(initial)^2+2ax
so, 0 = 1.5^2 + 2(-2.9)x, x = 2.25/(2*-2.9) = -.38793 the negative indicates that the direction of accel is opposite of direction of speed.
-0.39 meters is the answer.