Answer:
A. 490
Explanation:
soln
mass = m = 5kg
Height = h = 10m
Acceleration due to gravity = g = 9.8ms²
K.E = 1/2 × mass × (velocity)²
Recall from equations of motion
v² = u² + 2gh
Therefore,
K.E = 1/2 × mass × ( u² + 2gh)
K.E = 1/2 × 5 × ( 0² + 2×10×9.8)
K.E = 1/2 × 5 × 196
K.E = 1/2 × 980
K.E = 490 Joules
Answer:
F'= 4F/9
Explanation:
Two small objects each with a net charge of +Q exert a force of magnitude F on each other. If r is the distance between them, then the force is given by :
...(1)
Now, if one of the objects with another whose net charge is + 4Q is replaced and also the distance between +Q and +4Q charges is increased 3 times as far apart as they were. New force is given by :
.....(2)
Dividing equation (1) and (2), we get :

Hence, the correct option is (d) i.e. " 4F/9"
Answer:
C
Explanation:
Ray of light when hits any specimen or object. The light is partially reflected, partially reflected and partially absorbed. It is never completed reflected, refracted or absorbed. Hence, the correct answer would be c.
Cups
teaspoon
tablespoon
liters
milliliters
gallons
pints
tons
inches
Answer:
C. 30.6m
Explanation:
To find the height of the tower, we are to use Newtons law of motion to solve this problem. Since the penny is falling from the top of the tower, it is acted by the acceleration due to gravity. The formula to be used is:

Where H is the height of the tower, t is the time taken to hit the ground, u is the initial velocity and g is the acceleration due to gravity.
Given that, t = 2.5 s, g =9.8 m/s², u = 0 m/s (at the top of tower)
