a car is traveling at an average speed of 60km /hr and starts from a town at 9.45am. At what time will it reach another town 390 km away. (Please Explain)
Answers
Given :
Two objects of masses 100g and 200g are moving along the same direction with velocities of 2m/s and 1m/s.
After collision first object moves at a velocity of 1.67 m/s.
To Find :
Velocity of second object after collision.
Solution :
❒ Since no net force acts on the system, linear momentum of whole system is conserved.
We know that momentum is measured as the product of mass and velocity.
It is a vector quantity having both magnitude as well as direction..
SI unit : N s
★ Initial momentum of system :
➛ m₁u₁ + m₂u₂
➛ (100)(2) + (200)(1)
➛ 200 + 200
➛ 400 N s
★ Final momentum of system :
➛ m₁v₁ + m₂v₂
➛ (100)(1.67) + 200v₂
➛ 167 + 200v₂
Initial momentum of system is equal to the final momentum of system.
➠ 400 = 167 + 200v₂
➠ 200v₂ = 400 - 167
➠ 200v₂ = 233
➠ v₂ = 233/200
➠ v₂ = 1.16 m/s
Answer:
The work needed to be done is 156187 J.
Given :
Initial velocity(u) = 30 km/h = 30 × 5/18 = 25/3 m/s.
Final velocity(v) = 60 km/h = 60 × 5/18 = 50/3 m/s
Mass = 1500 kg
To Find :
Work needed to be done = ?
Solution :
We know the formula to calculate the work done,
So by using it,
➠ Work done = 1/2mv² - 1/2mu²
➠ W = m/2(v²-u²)
➠ W = 1500/2(50/3²-25/3²)
➠ W = 156187 J
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➤ Additional information :
Work is done when a force that is applied to an object moves that object or body!!
The work is calculated by multiplying the force by the amount of movement of an object itself !!
Formula = f × d
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