Last seen: Jan 25, 2021
When an object experiences a net zero external unbalanced force, in accordance with second law of motion its acceleration is zero. If the object was i...
Here, mass m = 1200 kg Initial velocity, u = 90 km h-1 = 90 x 5/18 = 25 m s-1 Final velocity, v = 18 km h-1 = 18 x 5/18 = 5 m s-1 Time, t = ...
The force of nail on the hammer, F = F = = = -2500 N Minus sign denotes the force exerted by the nail on the hammer is acting in the dire...
Here, mass of motorcar, m = 1200 kg Let each person exerts a force F on the motorcar. Total force of two persons = F + F = 2 F As this force gives a u...
(a) Here, u = 0 Using s = ut + ∴ Time in seconds - Distance in metres 0 0 0 1 ...
Here, m = 10 kg, s = 80 cm = 0.8 m, a = 10 ms-2 u = 0, v = ?, p = ? From, v2 - u2 = 2as, v2 - 0 = 2 x 10 x 0.8 = 16 or v = Momentum transferr...
Kiran’s suggestion is incorrect as momentum is always conserved, i.e., change in momentum of insect must be equal to that of motorcar. Akhtar’s sugges...
Here, m = 100 kg u = 5 ms-1 v = 8 m s-1, t = 6 s Initial momentum of object, p1 = mu = 100 x 5 = 500 kg ms-1 Final momentum of object, p2 = ...
Mass of object, m1 = 1 kg Velocity of object before collision, u1 = 10 ms-1 Mass of wooden block, m2 = 5 kg Velocity of wooden block before co...
Mass of bullet (m) = 10 g = 0.01 kg Initial velocity of bullet (u) = 150 m s-1 Final velocity of bullet (v) = 0 Time (t) = 0.03 s Acceleration o...
Mass of ball(m) = 200g = 0.2 kg Initial velocity of ball (u1) = 10 ms-1 ∴ Initial momentum of ball = mu1 = 0.2 kg x 10ms-1 = 2 Ns Final veloci...
Student’s justification is not correct. Two equal and opposite forces cancel each other if they act on the same body. According to the third law of mo...
Let the two object be A and B. Mass of object A, m1 = 1.5 kg Mass of object B, m2 = 1.5 kg Velocity of object A before collision, u1 = -2.5 ms...
The cabinet will move with constant velocity, if net external force acting on it is zero. Since a horizontal force of 200 N acts on the cabinet in the...
(b) mv2 Explanation: Momentum = mass × velocity = m × v = mv
Here, m = 1500 kg, a = -1.7 ms-2, F = ? F = ma F = 1500(-1.7)N = -2550 N Negative sign indicates that the force is opposing the motion of the ve...
(a) Net accelerating force = Force exerted by engine - Frictional force = 40000 - 5000 = 35000 N (b) Acceleration, a = = = 1.94 ms-2 (...
Here, m = 1 kg, u = 20 ms-1 v = 0, s = 50 m, F = ? From, v2 - u2 = 2as 0 - (20)2 = 2a x 50 = 100 a or a = = -4ms-2 Then, force of friction,...
Here, u = 0, s = 400 m t = 20 s, m = 7 tonnes = 7000 kg (i) Using, s = ut + 1/2 at2 400 = 0 + 1/2a x 400 = 200a a = 2 ms-2 (ii) F = ma = 700...
(c) there is a force on the ball opposing the motion Explanation: The cricket ball comes to rest after covering a short distance, because there is...