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Physics Exam number 8/2/ Physics #I

①A trangularblockymassM With also bo , and o a I mass m^ rests on^ the^ 60- ° side (a)

N +

fs +^ w =^0 ①s =^30 · N=^ WCsO^ N kn YgN N-WLosR =^ o (^) => N = W losO ⑪ fs - WSing^ =o (^) fs = WS^ in^ O to using

• #N Osuppin M (^45) Is: Tants I^ G =^0 = supply fs Ets) (^) u = wo ,)

N

Fig

N (^) = w Cos^ OS I Tan (^) Os W

have relative^

to the^ table^

to

Whathorizontal acceleration^ a^ most M keep m stationary relative to^ thetriangular block , assuming frictionless contacts?^ N +^ fs+ w^ =^0 mea (^) - O What^ huniontal (^) foc

f must be

applied to the (^) system to achieve^ this^ result , assuming a frictionless table top ? (^) fo -INSine^ = ⑳ (^) suppose no force in supplied to (^) M and^ both^ surfaces are frictioles.^ Describe the^ resulting motions.. (^) MsN = W^ Sin^ Es^ If (^) fs < (^) MsN.

Vertical

-........ Y =- 15 , 000 f

---

y

Voyt

1g

z

• (^) Voy =o

P y = zgt angle

i

x= Voxt

Y

• honzontal

Auste sight

x -^ O2 Fant^ Yy

A bomber^ is^ flying at (^) a constant^ houzontal^ velocity^ at 400mls at (^15) , 000 It^ towards a point directly above its^ target At what^ angle of righto should (^) a bond^ be^ released to strike the^ target. Show the^ trajectory (^) of the bomb.

4 . A (^) soccer player kicks (^) a ball (^) at (^) an angle of^

from

the

horizontal with^ an^ initial speed (^50) mls

. (A right (^) angle, one of those angles is 37 ,

has side^ in^

the natio^3 :^4 : 5 , or 6 : 8 :

Assuming that the^ ball moves^ in a^

vertical

place : @ Find the time^ t , at which^ the ball^ reaches (^) the highest ⑨ (^) Vy = (^) Vo (^) sint-gt point (^) % it trajectory

. t= Vosinto-Vy

• (^) * g ⑥ How high^ does the ball go ? A y = 0 , vo (^) = 50m/s 0 23] 929 · 81 mys"- ⑳ what is the hizontal range the a & What is the (^) velocity of the ball (^) as it strikes the (^) ground ?

x = (V cos00) + Range = (^) (vo Costo) t Vy = No^ Sino-gt therefore V =

Vya tant= Vy/Uz ⑤ A = v2 (^) where V = (^239) , 000

• r V =^2 Tr where^ T=^27 . 3 days

T

One (^) dimentio (^) motion

replacement DX = x)

• x, speed = velocity 2 ; ff -t; az (^) Du DE
• (^) I · a = Econstant

u

v= V (^) + at

u = (^) u (^) + at

Example A block^ is (^) at rest^ on an inclined place (^) making an angle & with^ the horizontal^ Y go" 3

• ** As the^ angle of the (^) inclined in (^) raised ,

it

is found that slipping Just begins at an^ angle (^) of inclination (^) &S (^). What is (^) the coefficient of static friction between block^ and (^) incline? The block is^ at^ west , so that N +^ fs

W (^) = 0

Resolving a andy components (^) , (^) along the^ plane and the^ normal to the^ place ,^ respectively , we oblaci N-ixCost (^) = o fs- W^ Sin0^ =^ D fo EMsN If we^ increase the (^) angle of incline slowly until stipping just (^) begins , for^ that angle, (^0) -Os , we can ose fs2 (^) Ms N

. (^) N =^ X^ Cost MsN

= VY^

sinOs us = Tan (^) Os The angle of inclination (^) at which slipping Just starts

A baseball^ weighing^ 0/kg is^ struck^ by a^ bat while^ itis in hunizontal^ flight^ with (^) a speed of 90mp^ After leaving the

but the^

ball travels will^ a speed of 110 mys in^ a^ direction opposite to its^ original

mution. Determine the

impulses of^ the collision. We cannot^ determin the impale from the definition J = S Fat because we^ do^ not^ know^

the

firce exerted on the ball (^) as (^) a function (^) of time. However impulse = charge in momentum^ = P-P, = (^) mrz- (^) Mr = (V-4) magnitude y impulse is therefore (floms-aoms) = (^) Kea