1. A mass of 0.5 kg is held by a spring balance. The scale reads 8 N when the balance is suddenly lifted.The acceleration while lifting is
A. 2 ms-2
B. 4 ms-2
C. 6 ms-2
D. 8 ms-2
E. 16 ms-2
Physics Mock Question
2007-04-02 11:00 pm
回答 (2)
2007-04-03 2:59 am
Take upward as positive.
Let Fnet be the net force acting on the mass, and F1 be the sudden force acting on the mass. (只係比你睇，如果要show step, 可以唔洗寫E步)
Fnet = ma
F1 – mg = ma (the net force acting on the mass = the sudden upward force – the gravitational pull of the earth to the mass)
8 – (0.5)(10) = (0.5)a
a = 6 ms-2
∴The answer is C 6 ms-2
Let Fnet be the net force acting on the mass, and F1 be the sudden force acting on the mass. (只係比你睇，如果要show step, 可以唔洗寫E步)
Fnet = ma
F1 – mg = ma (the net force acting on the mass = the sudden upward force – the gravitational pull of the earth to the mass)
8 – (0.5)(10) = (0.5)a
a = 6 ms-2
∴The answer is C 6 ms-2
2007-04-02 11:35 pm
重物受兩個力: 重力mg=0.5kgx10m/s^2=5N (向下)
彈簧的拉力(即讀數)=8N(向上)
合力F=ma 即 8N-5N=0.5kgxa(向上)
a=3/0.5=6m/s^2
彈簧的拉力(即讀數)=8N(向上)
合力F=ma 即 8N-5N=0.5kgxa(向上)
a=3/0.5=6m/s^2
收錄日期: 2021-04-22 00:30:26
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