[单选题]
An object is launched with a
pyp 5p 3y48b2- qrmq*d i9kuxigg5 8psn angle of θ from the ground and an initial ve
xn3/gf. j1*j7-kmrxjc8 qso4 v8 fp gklocity of
jn.mqxk7 1r o v jg83ff/psjk-*gx4c 8 v.
Which graph shows the variation of the horizontal component $v_h$ of the velocity of the object with time t? (Air resistance is not ignored)
A.
B.
C.
D.
参考答案:
B
本题详细解析:
Explanation:
The object starts its motion with non-zero horizontal velocity. Due to air resistance, It experiences negative acceleration (opposite to the direction of motion). The force from air resistance is proportional to the speed of the object. Since a decrease in speed results in a decrease in air resistance, the magnitude of negative acceleration should decrease over time. The gradient of the v−t graphs indicates acceleration. The only graph that has a decreasing negative gradient is B. Therefore, the answer is B.
