Answer
given,
mass of the drop, m = 0.0014 g
speed of the drop, u = 8.1 m/s
a) Change in momentum is equal to impulse
final velocity of the drop, v = 0 m/s
J = m ( v - u )
J = 0.0014 x 10⁻³ x ( 0 - 8.1 )
J = -1.134 x 10⁻⁵ kg.m/s
impulse of the roof = - J = 1.134 x 10⁻⁵ kg.m/s
b) time, t = 0.37 m s
impact of force = ?
we know
J = F x t
1.134 x 10⁻⁵ = F x 0.37 x 10⁻³
F = 0.031 N
the magnitude of the force of the impact is equal to F = 0.031 N
the key result indicate that how you will achieve the your goal
Answer:

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♨ Question :
- A car starts from rest and is moving at 60.0 m/s after 7.50 s. What is the car's average acceleration ?
♨ 
☄ Given :
- Initial velocity ( u ) = 0
- Final velocity ( v ) = 60.0 m/s
- Time ( t ) = 7.50 s
☄ To find :
✒ We know ,

Substitute the values and solve for a.
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✑ Additional Info :
- When a certain object comes in motion from rest , in the case , initial velocity ( u ) = 0
- When a moving object comes in rest , in the case , final velocity ( v ) = 0
- If the object is moving with uniform velocity , in the case , u = v.
- If any object is thrown vertically upwards in the case , a = -g
- When an object is falling from certain height , in the case , final velocity at maximum height ( v ) = 0.
Hope I helped!
Have a wonderful time ツ
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Answer:
strontium has 50 neutrons
Answer:
1. Static electricity is caused by the build up of electrical charges on the surface of objects, while current electricity is a phenomenon from the flow of electrons along a conductor. 2. When objects are rubbed, a loss and/or gain of electrons occurs, which results in the phenomenon of static electricity.
Explanation: