Answer:
Density is defined as mass per unit volume. its SI unit is: kg/m³
Explanation:
B. The gravity acceleration is in the same direction as the force of gravity, and thus towards the centre of the earth
Answer:
Explanation:
Given
Free fall acceleration on mars 
Time Period of pendulum on earth 
Time period of Pendulum is given by

for earth



(b)For same time period on mars length is given by



Answe
given,
mass of the bar, m = 30 Kg
distance of rise, h = 0.60 m
Assuming the efficiency = 25 %
energy from the pizza slice = 300 C = 1260 kJ
To consume Energy from the pizza bar is to be pulled several number of time.
( energy from pizza ) x (efficiency) = n m g h
n is the number of lift
( 1260 x 10³) x (0.25) = n x 30 x 9.8 x 0.6

n = 1786 times.
Weightlifter should lift bar 1786 times to burn off the energy.
When you set a heavy bag down on the ground, you are doing negative work on it.