Answer:
The weight of the wheelbarrow and the road is 784 N and the force required to lift the wheelbarrow is 784 N.
Explanation:
Given that,
The total mass of the wheelbarrow and the road is 80 kg.
The weight of an object is given by :
W = mg
where
g is acceleration due to gravity
So,
W = 80 × 9.8
= 784 N
So, the force required to lift the wheelbarrow is equal to its weight i.e. 784 N.
There can be an experiment run using two or more cleansers at the same time as the manufacturers' one
Answer:
Mass of the car is 1576 kg.
Explanation:
Let the mass of the car be
kg.
Given:
Initial velocity of the car is, 
As the car stops, final velocity of the car is, 
Change in momentum is, 
Now, we know that, momentum is given as the product of mass and velocity.
So, change in momentum is given as:

Therefore, the mass of the car is 1576 kg.
Answer:
100years later
Explanation:
Because the lights will arrive at world after 100 years later.