The answer to your quesiton is,
A) Venus has phases.
-Mabel <3
Answer:
The rock's speed after 5 seconds is 98 m/s.
Explanation:
A rock is dropped off a cliff.
It had an initial velocity of 0 m/s. And now it is moving downwards under the influence of gravitational force with the gravitational acceleration of 9.8 m/s².
Speed after 5 seconds = V
We know that acceleration = average speed/time
In our case,
g = ((0+V)/2)/5
9.8*5 = V/2
=> V = 2*9.8*5
V = 98 m/s
Answer: Option D: 5.5×10²Joules
Explanation:
Work done is the product of applied force and displacement of the object in the direction of force.
W = F.s = F s cosθ
It is given that the force applied is, F = 55 N
The displacement in the direction of force, s = 10 m
The angle between force and displacement, θ = 0°
Thus, work done on the object:
W = 55 N × 10 m × cos 0° = 550 J = 5.5 × 10² J
Hence, the correct option is D.
Increasing its velocity will add to the kinetic energy more as the formula for kinetic energy is 0.5*m*v^2. (The speed will be squared making it greater)