A block of mass 15kg is placed on a long trolley. The cofficient of fricition between the block and trolley is 0.18. The trolley accelerates from rest

Monjur Alahi

A block of mass 15kg is placed on a long trolley. The cofficient of fricition between the block and trolley is 0.18. The trolley accelerates from rest with `0.5m//s^(2)` for 20s. then what is the friction force:-
A. 3.5N
B. 133.3N
C. 7.5N
D. N.O.T.


0 like 0 dislike
1 views
Share with your friends

1 Answers

Salim Ahmed Kawsar

Call

Correct Answer - C
Pseudo force `=15xx0.5=7.5N`
`f_("max")=15xx10xx0.18=27N`
`therefore f=7.5N`

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
A book sits on a horizontal top of a car which accelerates horizontally from rest. If the static coefficient of friction between car top and book is `

Correct Answer - D `a_("max") = (mu mg)/(m) = mu g`

2 Answers 1 views
The hysteresis loss for a specimen of iron weighing 15kg is equivalent at `300Jm^(-3)cycle^(-1)` Find the loss of energy per hour at 25 cycle `s^(-1)`

Let Q be th energy dissipated per unit volume per hystersis cycle in the given sample. Then the total energy lost by the volume V of the sample in time...

2 Answers 1 views
A body of mass m accelerates uniformly from rest to velocity `v_(0)` in time `t_(0)`. What is the instantaneous power delivered to the body when its v

Correct Answer - C Acceleration `a = (v_(0))/(t_(0))` Force on the body `F = (mv_(0))/(t_(0))` Instantaneous Power `= P = (mv_(0))/(t_(0)) (v_(0))/(2) = (mv_(0)^(2))/(2t_(0))`

2 Answers 1 views
Assertion In front of a concave mirror, a point object is placed between focus and centre of curvature. If a glass slab is placed between object and m

Correct Answer - C (c) Glass slab will shift the object towards mirror. If it comes between pole and focus the image will become virtual.

2 Answers 3 views
Two persons are holding a rope of negligible weight tightly at its ends so that is horizontal. A 15kg weight is attached to the mid point which how no

Correct Answer - D Horizontal force can not balance vertical forces.

2 Answers 1 views
A block of mass 0.1 is held against a wall applying a horizontal force of 5N on block. If the coefficient of friction between the block and the wall i

Correct Answer - C `f_("max")=0.5xx5=2.5N` `F_("req")=mg=0.98=0.98N`

2 Answers 1 views
A block of mass m is lying on an inclined plane. The coefficient of friction between the plane and the block is `mu`. The force `(F_(1))` required to

Correct Answer - A `F_("req")=mg sin theta+mu mg cos theta`

2 Answers 1 views
If a car at rest, accelerates uniformly to a speed of `144 km//h` in `20s`, it covers a distance of

Correct Answer - B `v=144xx(5)/(18)=40 m//sec t=20` sec `s=((u+v)/(2))t=((0+40)/(2))20=400m`

2 Answers 2 views
A car of mass 1000 kg accelerates uniformly from rest to a velocity of 15 m/s in 5 sec. The average power of the engine during this period in watts is

`F=1000((15-0)/(5))=3000N` `ltPgt `ltPgt = ([(1)/(2)(1000)(15)^(2)-0])/(5)=22500" Watt"`

2 Answers 1 views
A ball strikes a horizontal floor at `45^(@)`. 25% of its kinetic energy is lost in collision. Find the cofficient of resultation

`((1)/(2)mU^(2)-(1)/(2)mV^(2))/((1)/(2)mU^(2))=(1)/(4)rArrV=Usqrt((3)/(4))` `V=sqrt((3)/(4))U=[((U)/sqrt(2))^(2)+((eU)/sqrt(2))^(2)]^(1//2)` `e=(1)/sqrt(2)`

2 Answers 1 views
X