Answer:
16000
Explanation:
Mass(m)=2Kg (1kg= 1ooo g then 2 kg=2000 g)
Velocity(v)= 4 meter
Acceleration due to gravity (g)=10m/s
We know that,
P.E= 1/2 mv^2
or, 1/2 × 2ooo × 4^2
or, 1/2×2000 ×16
or, 2000×8
Therefore= 16000
Answer:
Speed of the boat, v = 4.31 m/s
Explanation:
Given that,
Height of the bridge, h = 32 m
The model boat is 11 m from the point of impact when the key was released, d = 11 m
Firstly, we will find the time needed for the boat to get in this position using second equation of motion as :
Here, u = 0 and a = g
t = 2.55 seconds
Let v is the speed of the boat. It can be calculated as :
v = 4.31 m/s
So, the speed of the boat is 4.31 m/s. Hence, this is the required solution.
to be franc i really think the answer is B
a) we can answer the first part of this by recognizing the player rises 0.76m, reaches the apex of motion, and then falls back to the ground we can ask how
long it takes to fall 0.13 m from rest: dist = 1/2 gt^2 or t=sqrt[2d/g] t=0.175
s this is the time to fall from the top; it would take the same time to travel
upward the final 0.13 m, so the total time spent in the upper 0.15 m is 2x0.175
= 0.35s
b) there are a couple of ways of finding thetime it takes to travel the bottom 0.13m first way: we can use d=1/2gt^2 twice
to solve this problem the time it takes to fall the final 0.13 m is: time it
takes to fall 0.76 m - time it takes to fall 0.63 m t = sqrt[2d/g] = 0.399 s to
fall 0.76 m, and this equation yields it takes 0.359 s to fall 0.63 m, so it
takes 0.04 s to fall the final 0.13 m. The total time spent in the lower 0.13 m
is then twice this, or 0.08s
