Please just complete which ever questions you can I really would appreciate it.

Question

Please just complete which ever questions you can I really would appreciate it. If you all can solve any of these questions please try and show the work and answer that you did in order to receive your answer I just want to be able to understand is all Thanks.

1.) An object is projected off the edge of a table ( At the top of the projectiles height it is 6.74 cm and the starting angle is 50 degrees). Use this data to find the initial speed of the object?

2.) A weight is hanging from 2 cables B and C from the ceiling. The force of the block is 72 and the the angles for both cables from the ceiling is 60 degrees. Please find the tension in cables B and C?

3.) A dockworker applies a constant horizontal force of 80 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves 11.0 m in the first 5.00s. What is the mass of the block of ice?

4.) A 6kg mass sits on a frictionless table connected by a wire over a pulley to an 8kg mass. Find the acceleration of the hanging block?

Explanation / Answer

problem 1.

y^2max. = u^2.sin^2/2g

where ymax = maximum height attained

u = initial velocity, = angle of projection, g = acce. due to gravity

putting ymax = 6.74 cm = 0.0674 m, g = 9.8 m/s2 and = 50 degree

we get u = 0.38 m/sec

since angle it makes with the ceiling is 60 degree.

hence component of tension acting upward = Tsin60 + Tsin60 (total force by both cable)

and downward force = 72 N

so, 2Tsin60 = 72

T = 41.56 N

problem 3

change in kinetic energy = totak work done-----------------eqtn 1

initial K.E = 0   

at t = 5 sec , K.E = 1/2 * m * v^2 where m = mass and v = velocity at t =5 sec

change in K.E = 1/2 * m * v^2

work done = net force * displacement

= 80 * 11 = 880 J

now using s = u.t + 1/2 * a *t^2

11 = 0 + 1/2 * a * 25

a = 0.88 m/sec2

now v = u + a*t

v = 0 + 0.88 * 5 = 4.4 m/sec

putting value of v = 4.4 in eqtn 1 we get

1/2 * m * (4.4 * 4.4) = 880

m = 90.9 Kg

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---