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Physics 170 Midterm 1
Name, Roster #
The following information pertains to questions 1- 5
A particle of mass 2.0 grams moving in one dimension has a position as a function of time given by m m x ( t )=at 3 - b t2 where: a=2.0 and b=6.0. Assume the positive x direction points S S to the right
- What is the magnitude and direction of the particle's instantaneous velocity at t=1.0 seconds?
Answer
- What is the magnitude and direction of the particle's average velocity between t=O and t=1.0 seconds?
Answer
- What is the furthest point to the left that the particle reaches after t=O.O s
- What is the magnitude and direction of the particle's instantaneous acceleration at t=3.0 s?
~ ( 3 = ) l a - , -12 + ~ 4 5 z " -
Answer
5. What is the magnitude and direction of the net force acting on the particle at t=3.0 s?
Answer
Physics 170 Midterm 1
Name, Roster #
The following information pertains to questions 6- 9: The planet "Henweigh" is very useful for performing kinematics experiments because it has no atmosphere, and the acceleration of gravity close to the surface is 5.00 m/s2 down. On the planet "Henweigh, a ball is kicked from the ground such that the horizontal component of its initial velocity is
10.0 d s and the vertical component of its initial velocity is 15.0 d s.
- What is the highest point above the ground that the ball reaches?
a. 22.0 m cz-3 c. 31.6 m (^) on d. 37.5 m e. 40.0 m f. 49.4 m
- What is the speed of the ball at its highest point? (^) ~ ~ ~ 4 c Cp h d , 4- 5 3 5
- How far does the ball travel horizontally while it is in the air? b ; r - ~. f oy- + 65 ~ ~
- What is the magnitude of the ball's velocity the instant before it hits the ground?
- In general, when does an object speed up?
a. When it has a negative acceleration. b. When it has a positive acceleration. O w h e n it's velocity and acceleration are pointing in the same direction. d. When it's velocity and acceleration are pointing in opposite directions.
Name, Roster # Physics 170 Midterm 1
- A particle is moving in a clockwise circle. If the particle is slowing down, which arrow best represents
the net acceleration of the particle at the point marked X?
a. - b. - c. 1 d. f
e. f f a g. J I,.\
- A 10.0 kg object is sitting on a scale and has a rope attached to it as shown. If the scale reads 38.0 N, what is the tension in the rope?
---- Scale
b. 70.0N c. 98.0 N d. 126N e. 136 N
The following information pertains to questions 18-20:
Giventhetwovectors: 2=+2;-4f+3i g=-3f+5i
- What is the magnitude of A - B?
- Find a vector that is perpendicular to vectors 2 and 5
3 - a k a ; - 1 j
- 4 T F
- What is the angle between vectors 2 and 5?
A 5 4flca3e -3 ,- ,I A - f l. C>>^ cl.^^4^4^1 -^1 A^5^1 0 5 co5 - A
Answer
Answer ( 3 1
Answer
Name, Roster # Physics 170 Midterm 1, Problem 1
Our hero Fred (his mass is 100 kg) has taken up Olympic Weightlifting. Fred is shown below lifting a barbell of mass 220 kg. At the instant shown, the weights have an upward acceleration of 2.00 rn/s
a. On the figures of Fred and the barbell shown below complete the Free - body
forces that act on the respective objects. (6 points)
+ !i 0 ; 2 $q*
J b. What is the magnitude and direction of the force exerted on the barbell by Fred at the instant shown? (7 points)
c. What is the magnitude and direction of the normal force exerted on Fred's feet by the floor at the instant shown?(7 points)
