Answer:
0.9 N
Explanation:
The force exerted on an object is related to its change in momentum by:
where
F is the force exerted
is the change in momentum
is the time interval
The change in momentum can be rewritten as
where
m is the mass
u is the initial velocity
v is the final velocity
So the formula can be rewritten as
In this problem we have:
is the mass rate
is the initial velocity
is the final velocity
Therefore, the force exerted by the hail on the roof is:
Answer:
water are heavier than patrol . Because petrol have less density than water ...
Answer:
Reduced by 10
Explanation:
It was said that the time was ten times more. For it to remain the same, the force must be ten times less. Because (1/10) x 10 = 1.
Answer:
0.035 (3.5 %)
Explanation:
The thermodynamic efficiency is given by:
where
is the cold temperature
is the hot temperature
In this problem we have
So the efficiency is
Answer:
I = 1.36 x 10⁻⁴ W/m²
Explanation:
The intensity of the sound produced by the Elephant can be calculated by using the following formula:
where,
I = Intensity of sound = ?
P = power of sound = 0.45 W
A = area = πr² = π(32.5 m)² = 3318.3 m²
Therefore,
<u>I = 1.36 x 10⁻⁴ W/m²</u>
