Deck 2: Linear Motion, and Stress and Strain

Question 1

An object moves from rest in a straight line with a uniform acceleration and takes 5 s to cover the first 100 m. It then continues with the same acceleration for another 100 m. The velocity after the 100 m is:

A) 25 m/s
B) 40 m/s
C) 160 m/s
D) 200 m/s

Answer 1

B

Question 2

An object moves from rest in a straight line with a uniform acceleration and takes 5 s to cover the first 100 m. It then continues with the same acceleration for another 100 m. If the object continues with the same acceleration, the time taken to cover the next 100 m will be:

A) 2.1 s
B) 5.0 s
C) 7.1 s
D) 10.0 s

Answer 2

A

Question 3

An object moves from rest in a straight line with a uniform acceleration and takes 5 s to cover the first 100 m. It then continues with the same acceleration for another 100 m. The velocity after the total distance of 200 m will be:

A) 40.0 m/s
B) 56.6 m/s
C) 80.0 m/s
D) 160 m/s

Answer 3

B

Question 4

An object falls freely from rest. If it falls through a distance s in the first second, the distance it will fall through in the second second is:

A) 1s
B) 2s
C) 3s
D) 4s

Question 5

Decide whether each of these statements is True (T) or False
For a velocity−time graph:
(i) The distance travelled between two times is the area under the graph between the ordinates for those times.
(ii) The acceleration at any instant is the gradient of the graph at that time.

A) (i) T (ii) T
B) (i) T (ii) F
C) (i) F (ii) T
D) (i) F (ii) F

Question 6

The following is a force−extension graph for strips of materials A, B, C and D, each
Having initially the same cross-sectional area and length. When the strip is used as a cantilever, which one will sag the most when force F is applied to the free end?

A) A
B) B
C) C
D) D

Question 7

For a material with a tensile modulus of elasticity of 200 GPa, the strain produced by a stress of 50 MPa, assuming the limit of proportionality is not exceeded, will be:

A) 0.000 25
B) 0.25
C) 4
D) 4000

Question 8

The maximum tensile force a rectangular steel bar of cross-section 20 mm % 10 mm can withstand, if it has a tensile strength of 800 MPa, is:

A) 16 kN
B) 25 kN
C) 160 kN
D) 2500 GN

Question 9

A rectangular bar has a cross-sectional area of 40 mm2. The tensile stress produced when it is stretched by axial forces of 100 N is:

A) 0.4 MPa
B) 2.5 MPa
C) 25 MPa
D) 40 MPa