A spear is thrown at you at a very high speed. As it passes, you measure its length as one-half its normal length. From this measurement, you conclude that the moving spear's mass must be
A) one-half its rest mass.
B) twice its rest mass.
C) four times its rest mass.
D) zero.
B
You might also like to view...
Describe how Einstein used the photoelectric effect to support the particle theory of light and photons
What will be an ideal response?
When a spinning ice skater pulls in his arms, he spins faster because
A) his angular momentum must be conserved, so reducing his radius must increase his speed of rotation. B) there is less friction with the air. C) there is less friction with the ice. D) there exists an unbalanced reaction force.
A gallon container is filled with gasoline. How many gallons are lost if the temperature increases by 25°F? (The volume expansion of gasoline is 9.6 × 10?4 (°C)?1.) (Neglect the change in volume of the container.)
A. 2.4 × 10?2 B. 1.3 × 10?2 C. 3.6 × 10?2 D. 4.8 × 10?2 E. 9.6 × 10?2
A proton initially moves left to right long the x axis at a speed of 2.00 × 10^4 m/s. It moves into an electric field, which points in the negative x direction, and travels a distance of 0.200 m before coming to rest. What acceleration magnitude does the proton experience?
a. 2.67 × 10^12 m/s2 c. 6.67 × 10^6 m/s2 b. 9.33 × 10^9 m/s2 d. 1.00 × 10^9 m/s2